JP5154572B2 - Methods and devices for laminectomy and laminoplasty - Google Patents

Abstract

This invention relates to a technique for performing laminar osteotomy (dividing of the spinal lamina, a posterior structure of vertebra). The term osteotomy is derived from os (bone), tomy (to cut or remove), and laminoplasty (the reshaping of the lamina). This technique can be performed with or without visual assistance such as cameras used with endoscopy, or image guidance such as fluoroscopy, computer tomography (CT) or magnetic resonance imaging (MRI).

Description

  This application relates to US Provisional Patent Application 60 / 874,970 (filed December 15, 2006) and US Provisional Patent Application 60 / 963,310 (filed August 3, 2007). Each is incorporated herein by reference in its entirety.

  The present invention is a minimal for performing laminoplasty and laminoplasty with or without visual or image assistance such as endoscopy, fluoroscopy, cameras used in CT or MRI. Invasive surgical (MIS) methods and devices.

  Spinal stenosis is a condition characterized by stenosis of the central spinal canal or intervertebral foramen. Spinal stenosis causes pain in the back and feet due to compression of the spinal nerve. Severe cases of spinal stenosis require spinal decompression laminectomy or spinal laminoplasty to enlarge the spinal canal and relieve pressure on neuronal elements. These neuronal elements consist of the spinal cord, spinal cone, nerve roots, and all other structures covered by the dura mater (the connective tissue membrane covering the neuronal elements). Pressure on neuronal elements is relieved by partially or completely removing or reshaping structures that are sources of compression that may include bone or soft tissue (ligaments, joint capsules, and other non-bone structures).

  Spinal stenosis is considered to be primary (congenital) or secondary (acquired). Isolated primary spinal stenosis is very rare and involves congenital anomalies or spinal stenosis resulting from disease in the developmental process. Secondary stenosis usually results from degenerative changes.

  Reduced laminectomy is a standard surgical tool for patients with spinal stenosis when non-surgical procedures are unsuccessful. Traditionally, surgery is performed by a dorsal approach to a prone patient with general anesthesia. In this dorsal approach, after the sterile field is created, a longitudinal incision is made along the midline of the back at the stenosis level. An incision is made down to the dorsal element that identifies the spinous process, lamina, and facet joint. Usually, radiopaque markers are used to obtain x-rays or other fluoroscopic images to ensure that the spinal level to be corrected is exposed. Systematic removal of the musculotendonous attached to the dorsal element exposes the spinal structure. The facet joint can be partially or completely removed based on current pathology. Removing a significant portion or all of the facet joints can make the spine unstable. In such cases, spinal fusion is generally required to stabilize the spinal column.

  Another surgical method of creating additional space in the spinal canal is called laminoplasty. In this technique, the lamina is divided and spread apart, and bone grafts are inserted to expand the space available for neuronal elements. The laminoplasty can be performed using a single-open or fenestration laminoplasty. In single-open or fenestration laminoplasty, the lamina on one side of the spine is completely divided, while the lamina on the other side is partially cut to form a hinge. The spinal dorsal element pivots about this hinge and inserts the graft into the opening to increase spinal canal space. Another laminoplasty, called double door or French door laminoplasty, completely divides the spinous process (where the lamina meets the midline). Cut each lamina halfway on either side of the back midline to form two hinges. The separated dorsal element opens with the cut spinous process, and the graft is inserted into the opening to again enlarge the spinal canal opening.

  Traditionally, laminectomy and laminoplasty are open surgical procedures that have long recovery times for patients and increase the cost and risk of complications. Accordingly, there is a need for tools that perform MIS techniques and laminectomy and laminoplasty. Furthermore, MIS technology has become more widely known in the surgical sub-specialty. Standard open surgery has been improved to be less invasive with the goal of reducing recovery time, reducing mortality, and reducing costs. For example, new tools and visualization techniques are used to reduce the incision to reduce patient recovery time and risk despite the same surgery. The other MIS methods described in this document attempt to achieve the same result with a completely new approach.

  Various surgical techniques have been reported for the treatment of spinal stenosis, including laminotomy, laminectomy, and laminoplasty. All of these techniques rely on either anatomy visualization or fluoroscopy or simple X-ray techniques, either directly or with the aid of a visual imaging instrument such as a camera. These procedures are performed using the technique of “rongeuring” (a French verb meaning to scrape or remove piece by piece) to remove or reshape the lamina. Other techniques describe deburring or scraping bone. However, all of these methods are performed by removing bone from the lamina longitudinal axis 9 perpendicular to the lamina longitudinal axis 8 (see FIGS. 1A and 2A).

  In US Pat. No. 6,358,254, Anderson discloses a method of performing spinal surgery in the lumbar spine to relieve spinal stenosis, cutting the spine with at least one pedicle and removing the spinal canal. In order to expand, the cut spine portion at the back of the facet joint is cut off from the vertebral body, and the separated portion is fixed to the vertebral body by mechanical means to heal the spine. In U.S. Patent No. 7,166,107 and U.S. Application No. 11/656790 (published as 200702219555), Anderson drilled a hole in the lumbar spine to insert a side cutting instrument and drill A method of dilating a lumbar spinal canal by cutting a pedicle from within is disclosed. The separated part is re-fixed to the vertebral body by mechanical means to be healed and the load-bearing function of the fixed vertebral structure is restored.

  However, known techniques and instruments do not provide a method for accurately and safely dividing the lamina with minimal risk of damaging neuronal elements. In particular, the method described by Anderson can be suitably used only for lumbar vertebrae with little or no risk of damaging the spinal cord or vertebral artery as in the case of the cervical or thoracic vertebra.

  In view of the above, one aspect of the present invention is directed to a method and device for separating lamina in a sagittal or oblique sagittal plane 8 that is oriented approximately in the longitudinal axis of the lamina, the separating instrument comprising: It faces either the head direction (cephalad) or the coccyx direction (caudate). This method of separating lamina is not disclosed in the open or image guide methodology. To perform this method of separating the lamina, one aspect of the present invention includes a novel guard inserted through the lamina inner cavity and protecting the laminar structures on both sides including neuronal elements. This guard functions to accurately guide bone division while minimizing the risk of damage to neuronal elements. In addition, segmentation, cutting, perforation, removal of spines, or other techniques to remove or segment bone compressing neuronal elements include CT scans, x-rays, fluoroscopy, MRI, or other techniques that guide segmentation Can be done under image guidance technology. In addition, designed to prevent the divided back element from moving forward by increasing the width of the divided back lamina or by reducing the width of the divided lamina covering the central tube A surgically implantable device is disclosed (see FIGS. 7A, 7B, and 9).

  One aspect of the invention described herein uses open surgical or MIS techniques, with or without image guidance using fluoroscopy, CT scan, X-ray, MRI, or other imaging techniques. This is an approach for performing laminectomy (laminectomy) and laminoplasty that can be performed. This technique has the advantage that it can be used to treat cervical, thoracic or lumbar regions of the vertebra.

  When this procedure was used in conjunction with CT or MRI guidance, it included the distance of lamellar bone from the skin, lamina thickness and depth, vertebral height, spinal canal area, skin incision for insertion. It has the uniqueness of being able to identify and measure the related anatomy including the angle of entry and position in three dimensions. Furthermore, the anatomy at risk of damage can be identified during this procedure and the relative safety of the procedure performed can be assessed.

  In one aspect of the present invention, a method of performing laminoplasty or laminoplasty using a dividing instrument on a sagittal or oblique sagittal plane facing the longitudinal axis of the lamina is proposed. . In this method, at least one lamina portion to be split is identified, a guard is placed proximal to the lamina portion to be split, and the lamina is split. This guard protects the patient's sublaminar thecal sac and pari-laminar soft tissue structures. This guard also guides the divider into the lamina.

  In another aspect of the invention, a device is proposed that protects a patient's sublaminar dural sac and soft tissue structures around the lamina while performing a procedure on the patient's spinal lamina. The device is positioned proximal to the lamina, parallel to the longitudinal axis of the lamina. The device comprises a sublaminar wall and a laminar wall with a curved or angled leading tip, allowing the patient's lamina to be separated into upper and lower tissue. The walls above and below the lamina are part of the cannulated cylinder and can be accessed with surgical tools to place devices, drugs, or other therapeutic agents.

  In yet another aspect of the invention, a surgically implantable device is proposed. The device is placed on either one or both of the divided edges of the patient's lamina. This device prevents forward movement or rotation of the segmented posterior spinal element after laminectomy.

  In another aspect of the invention, a method for performing laminectomy or laminoplasty using fluoroscopy, CT, MRI, ultrasound, or X-ray guidance is proposed. The method includes the steps of locating the patient's skin incision, guiding to guide the guidewire through the soft tissue and into the bone, and inserting the device through the incision and along the guidewire path. Positioning the device proximal to the lamina and protecting the patient's sublaminar dural sac and soft tissue structures around the lamina. The device comprises a sublaminar wall and a laminar wall with a curved or angled leading tip, allowing the patient's lamina to be separated into upper and lower tissue. The walls above and below the lamina are part of the cannulated cylinder. This method discloses the step of inserting a saw, drill, deburring, or other lamina splitting mechanism into the lamina through the cannulated cylinder of the device to completely divide or partially modify the lamina.

Further objects, features, and advantages of various aspects of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating exemplary embodiments of the present invention. However, the present invention is not limited to the exact configuration and instrument shown in the figures.
FIGS. 1A, 1B, and 1C show the side, posterior, and axial planes of the cervical spine with anatomical sites labeled. FIGS. 2A, 2B, and 2C show the side, posterior, and axial planes of the lumbar spine with anatomical sites labeled. FIG. 3 is a diagram showing a patient in a prone state with the longitudinal axes of the cervical vertebra, thoracic vertebra, and lumbar vertebrae. FIG. 4 shows a device according to an embodiment of the present invention assembled on a CT scanner table using various members. FIG. 5A is a CT scanner graphic in which the patient is in a prone state and the device according to the present invention is positioned along the patient's cervical spine. FIG. 5B is a CT scanner graphic in which the patient is prone and the device according to the present invention is placed on the patient's lumbar spine. FIG. 5C is a CT scanner graphic with the patient in a prone state and the operator standing in place. FIG. 5D is an axial view of the CT scanner, with the patient in a prone state. FIG. 6A is a side view of a patient, showing the exposed lamina after incision of the patient's back along the longitudinal axis of the lamina. The dilator is placed up to the lamina at the incision. A guide wire is placed through the dilator and guides the lamina splitting mechanism to the lamina. FIG. 6B is a side view of the patient, showing the lamina guard traveling in the dilator tube in the direction of the lamina along the longitudinal axis of the lamina. FIG. 6C is an enlarged view of the lamina with the lamina guard fully advanced, showing a safety stop that prevents the lamina guard from being advanced into the spinal canal. The side length of the lamina guard is the length that serves as a safety device to prevent the lamina guard from going to the central spinal canal. FIG. 6D is an enlarged view of the lamina with the lamina guard fully advanced, with additional hinge configurations, showing a safety stop that prevents the lamina guard from going into the spinal canal. FIG. 6E is a side view of the patient, showing the lamina guard traveling over the lamina along the longitudinal axis of the lamina. A lamina splitting mechanism is located within the lamina guard. FIG. 6F is a side view of the patient, showing the lamina guard traveling over the lamina along the longitudinal axis of the lamina. The lamina division mechanism is advanced and the lamina is divided. FIG. 6G is a side view of the patient showing the lamina guard traveling over the lamina along the longitudinal axis of the lamina. A lamina splitting mechanism is located within the lamina guard. FIG. 6H is a side view of the patient, showing the lamina guard traveling over the lamina along the longitudinal axis of the lamina. The lamina division mechanism is advanced and the lamina is divided. FIG. 6I is an axial view of the spine, with the lamina guard on one lamina and the lamina already split on the other side of the spine. 7A and 7B are axial views of a spinal column with bilateral laminectomy, clipped to the edge of the divided lamina so that the divided part of the spine does not enter the space of the central canal (A clip without teeth and a clip with teeth) are arranged. FIG. 8 is a side view of a patient approaching multiple laminaes using the same skin incision. However, each lamina approaches along the vertical axis.

  Preferred examples, methods, and aspects of surgically implantable devices used to divide the spinal lamina and raise the dorsal sidewall of the central spinal canal are described in this section. This lamina remodeling or laminoplasty creates a larger space for neuronal elements in the central spinal canal. This method is particularly beneficial because it can be done by CT, MRI, or other image guidance. In addition, the technology can be applied to any spinal cervical, thoracic, and lumbar vertebral level.

  1-2 show a side view, a back view, and an axial view of the cervical and lumbar spines, respectively. The thoracic vertebra is not shown because it is similar in the anatomical region relevant to this description. The vertebral body 1 forms the front wall of the central tube 2. The spinous process 3 is a medial bone ridge where the lamina 4 intersects. This process lifts the split dorsal element of the spine, effectively expanding the posterior edge of the central canal, or “raising” the spine of the spine. The pedicle 5 extends forward from the lamina and forms the side wall of the central tube. The lamina inner space 6 is a space between adjacent laminaes and is covered with soft tissue called a yellow ligament. The face joint 7 is a joint that connects the spine on the back side. The longitudinal axis 8 and vertical axis 9 of the spinal lamina are shown in FIGS. Further, FIG. 3 shows the longitudinal axis of the lamina of different vertebrae in the cervical, thoracic and lumbar regions of the patient 10 prone on the procedure table 11.

  The lamina's vertical axis determines the angle at which the lamina is approached and the skin incision position to reach the target lamina. The patient (10) is lying prone, sideways or slightly sideways on the treatment table. If performed using open or fluoroscopic techniques, this procedure can be performed in the operating room. When performed using CT or MRI guidance techniques, it can be performed in a scanning room or in an operating room specifically equipped with such a scanning device. You may use the sedative agent by general anesthesia or local anesthesia. A myelographic image may be taken immediately prior to this procedure to better visualize the neuronal elements. This procedure may be performed in conjunction with neuron monitoring.

  Procedures performed in accordance with the present invention are useful for acquired lesions such as intervertebral disc herniation, compression fractures, facet joints, or hypertrophied ligaments as well as congenital lesions such as short pedicles or central canal stenosis.

  One embodiment of the present invention is shown in FIG. The lamina dividing mechanism 12 includes a stand 13 attached to the treatment table 11. This can be attached singly on one side of the treatment table or on both sides of the table for increased stability. The stand includes an arm 14 attached to the universal joint 15, and devices used for performing the procedure can be arranged so that they can be held in a stable state while imaging is performed. The control of the laminar splitting mechanism may be performed by a robot, otherwise using a computer, or manually. Alternatively, these methods and equipment can be used as freehand technology without the use of equipment stabilizers.

  Another embodiment of the present invention is shown in FIG. FIG. 5A shows a prone patient, with devices aligned to perform the procedure on the patient's cervical spine. In the preferred method according to one embodiment of the present invention, a CT scanner 16 is shown, but MRI or other imaging techniques can be used. FIG. 5B shows the patient in the prone position. Here, the device is positioned to the patient's lumbar spine. This procedure can also be performed on the thoracic spine. The operator 17 is shown in the position to perform the procedure on the cervical spine in FIG. 5C. A view from the axial direction of the patient and the CT scanner is shown in FIG. 5D.

  When using open surgery, a standard back surgical approach to the spinal column is performed after achieving a sterile field. When using image guidance, an initial image is obtained. Since the opening technique and the image guidance technique are modifications of each other, the method described above will be described with a focus on the use of a CT scanner. Spinal cord lesion levels are identified with a CT scanner. A trajectory line through the longitudinal axis of the lower lamina edge is used to identify the skin incision. After the skin incision is formed, a guide wire (18) having a round tip is passed along the determined locus to the lower edge (caudal side) of the lamina (FIG. 6A). This procedure can be performed from the caudal side to the cranial direction and from the cranial side to the caudal side, but in the method described herein, the procedure is performed from the caudal side to the cranial direction.

  Use the expander (19) or a series of expanders to increase the size of the access path. These dilators can be supported by equipment stabilizers. The lamina guard is connected to a cylindrical shaft 20, and an upper lamina guard 21 and a lower lamina guard 22 extend from this shaft. As shown in FIG. 6B, these guards are placed in the lamina inner space above and below the lamina to be treated. The lamina guard advances through the dilator (19) under image guidance. The lower (22) and upper (21) lamina guard walls surround the lamina (4) and form a safety stop that prevents the lamina guard from entering the lamina medial space between the central spinal canal (2) or vertebral arch (6). (FIGS. 6C and 6E). Once the lamina guard is securely secured around the lamina, the saw, drill, deburring, or other bone splitting mechanism (26) is lowered through the cylindrical shaft (20) until it reaches the lamina (4). The lamina (4) is divided using the dividing mechanism (26) (FIG. 6F). Based on the degree of stenosis or the anatomy of the lamina, the lamina guard may need to be advanced step-by-step under image guidance.

  In another aspect of the invention, the distance that completely divides the lamina (4) can be measured, ensuring that the lamina splitting mechanism (26) enters the central spinal canal (2) or the lamina inner space (6). To avoid this, the size of the lamina splitting mechanism (26) and lamina guards (22 and 21) can be adjusted to exactly the same length as the lamina (4) (FIGS. 6E-H).

  Lamina guard can be advanced using imaging techniques such as CT scan, MRI, X-ray, fluoroscopy, or other guidance. A variable lamina guard is available and the operator selects this length based on measuring the longitudinal length of the lamina by CT or other image analysis. The length of the lower and upper lamina guard walls that match the length of the lamina undergoing the procedure serves as a safety stop to prevent the lamina guard from going into the central spinal canal (FIGS. 6C, 6D). 6C and 6D show two variations of the lamina guard, which may be laminated by hinge 23 or lamina thickness, anatomical location, or the elasticity of the material used to manufacture the lamina guard. Shown with and without other similar mechanisms responsible for width variability. In the most preferred embodiment, the lamina guard is made of titanium.

  FIG. 6E is a detailed view of the lamina with the lamina guard fully advanced, showing a safety stop that prevents the lamina guard wall from entering the spinal canal (FIG. 6E). In this embodiment, the laminar split mechanism handle 24 having a fixing pin 25 is set to an appropriate length and is inserted into the cylindrical access shaft of the lamina guard. It can be seen that the lamina splitting mechanism is arranged to split the lamina along the longitudinal axis of the lamina. It should be noted that in this embodiment, the length of the saw blade or deburring tip, or other lamina splitting mechanism 26 corresponds to the length of the lamina and functions as an additional safety device. The blade retention mechanism is wider than the saw blade and cannot travel through the divided lamina edges, thereby preventing the saw blade from entering the central spinal canal (FIG. 6F). The use of alternative splitting devices such as deburring is illustrated in FIGS. 6G and 6H.

  The lamina splitting mechanism advances under image guidance and splits the lamina along the vertical axis. It should be noted that the length of the saw corresponds to the length of the lamina and serves as an additional safety device. The blade retention mechanism is wider than the saw blade or deburring tip and cannot advance into the divided lamina, thereby preventing the saw blade from entering the central spinal canal. An axial view of the spine is shown in FIG. 6I, with the lamina guard in place on one lamina and the other side lamina split.

  When bilateral laminectomy is performed, the same approach is performed on the contralateral lamina. While splitting the opposite side lamina, the first side lamina guard is held in place. When both laminas are split, the lamina guard rotates. The right guard rotates clockwise and the left guard rotates counterclockwise. This process lifts the dorsal element of the split spine and effectively expands the posterior edge of the central tube or “lifts the spine” of the spine. With the back side wall raised, the lamina clip 27 is located at the divided lamina edge. The lamina clip is positioned either on the lamina portion that is lifted back or on the portion that is still attached to the pedicle (FIG. 7A). Alternatively, the clip may have teeth on the inside surface and be more firmly fixed to the lamellar bone (FIG. 7B).

  FIG. 8 is a side view of a patient showing multiple approaches to one or more laminaes through the same incision in the skin by adjusting the angle of the approach relative to the longitudinal axis of the lamina (FIG. 8). The ability to treat multiple laminaes through a single small incision has obvious benefits for both patients and surgeons.

  FIG. 9 is a view of the spine with the rupture fracture 28 as viewed from the axial direction. FIG. 9 shows the displacement of the dorsal side wall in the central canal with acute compression of the bone marrow and has been treated by bilateral laminectomy in the manner contemplated by the present invention. FIG. 9 also shows the elevation of the back side wall of the central tube.

  Place the clip 27 to clean and aspirate the site. Alternatively, a cleaning and aspiration system incorporated into the procedure or device contemplated by the present invention may be used during the entire process. In another aspect of the invention, osteoinductive material, osteoconductive material, or other bone healing material is placed on the surface of the divided lamina to aid in healing the divided lamina.

  In another aspect of the present invention, the CT scan is repeated to reveal the path of myelographic dye to the area before stenosis occurs. This CT scan can also reveal an increase in the size of the central tube, ensuring that there is no easily visible dural leak or bleeding. This controlled CT scan shows that the procedure resulted in decompression of the spinal canal due to spinal stenosis.

  If the patient is squeezing the spinal cord or dural sac due to the dorsal nature of the spinal canal, the above procedure can be performed as a treatment.

  Spinal decompression via a minimally invasive approach, such as the intended decompression by the present invention, reduces the time that the patient spends in the hospital. There is less blood loss and fewer wound healing complications.

  Using the techniques contemplated by the present invention, decompression can be performed on patients who are not obese or at high risk of open surgical complications. The laminar splitting mechanism described herein cuts bone rather than soft tissue. This is a great advantage of this procedure. Furthermore, the safety guard implemented by the technique contemplated by the present invention addresses concerns regarding the safety of neuronal elements including the dural sac or spinal cord.

  Better visualization of nerve roots can be achieved by injection of contrast agent prior to the procedure (myelography). This is another way to ensure that the dural sac is not pierced during the procedure.

  The above-described procedure can also be performed on patients who are indicated for treatment of anterior spinal surgery, either discectomy and fusion, arthroplasty, or any other pre-procedure. There are additional advantages to performing the above procedure prior to anterior spinal surgery. For example, by increasing the spinal canal space where the neuronal element can be retracted to the dorsal side, the surgeon can reduce the amount and likelihood of pressure on the neuronal element during anterior spinal surgery. This method significantly improves patient safety limitations. Thus, techniques contemplated by the present invention may reduce the amount of spinal cord compression that may occur during anterior spinal surgery, such as anterior discectomy; fusion, or arthroplasty.

  It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Accordingly, the present invention is intended to cover modifications and variations of this invention which are within the scope of any claim and their equivalents.

  Although the present invention has been described in some detail, this description is given by way of example, and without departing from the spirit and scope of the present invention, those skilled in the art may make various changes in the conditions and order of steps. It is understood that it can be done.

DESCRIPTION OF SYMBOLS 1 Vertebral body 2 Central canal 3 Spinous process 4 Lamina 5 Pedicle 6 Lamina inner space 7 Face joint 8 Vertical axis 9 Vertical axis 10 Patient 11 Treatment table 12 Lamina division mechanism 13 Stand 14 Arm 15 Universal joint 16 CT scanner 17 Operator 18 Guidewire 19 Dilator 20 Cylindrical shaft 21 Upper lamina guard 22 Lower lamina guard 23 Optional hinge of lamina guard 24 Handle of lamina split mechanism 25 Fixing pin 26 Lamina split mechanism: saw blade, deburring, or other split device 27 Clip 28 Intervertebral disc Ruptured fracture fragment

Claims (9)

  A device for protecting a patient's sublaminar dural sac and soft tissue structures around the lamina while performing a procedure on the patient's lamina, wherein the device is disposed parallel to the longitudinal axis of the lamina and proximal to the lamina A device comprising a laminae wall and a laminae wall having a curved or angled leading tip so that the patient's lamina can be separated into upper and lower tissues, The lamina wall is part of a cannulated cylinder, and the lamina can be accessed using at least one surgical tool to place a device, drug, or other therapeutic agent, the device comprising the procedure A device that protects the surrounding structure of the patient's lamina from damage or failure of any surgical instrument used to perform the procedure.   A device for protecting a patient's sublaminar dural sac and soft tissue structures around the lamina while performing a procedure on the patient's lamina, wherein the device is disposed parallel to the longitudinal axis of the lamina and proximal to the lamina A device comprising a laminae wall and a laminae wall having a curved or angled leading tip so that the patient's lamina can be separated into upper and lower tissues, The lamina wall is part of a cannulated cylinder, and the lamina can be accessed using at least one surgical tool to place a device, drug, or other therapeutic agent, the device comprising a clip A device comprising the lamina instrumentation or other surgically implantable device comprising.   A device for protecting a patient's sublaminar dural sac and soft tissue structures around the lamina while performing a procedure on the patient's lamina, wherein the device is disposed parallel to the longitudinal axis of the lamina and proximal to the lamina A device comprising a laminae wall and a laminae wall having a curved or angled leading tip so that the patient's lamina can be separated into upper and lower tissues, The lamina wall is part of a cannulated cylinder, and the lamina can be accessed using at least one surgical tool to place a device, drug, or other therapeutic agent, the device inside the lamina A device that is inserted through a gap.   A device for protecting a patient's sublaminar dural sac and soft tissue structures around the lamina while performing a procedure on the patient's lamina, wherein the device is disposed parallel to the longitudinal axis of the lamina and proximal to the lamina A device comprising a laminae wall and a laminae wall having a curved or angled leading tip so that the patient's lamina can be separated into upper and lower tissues, The lamina lower wall is part of a cannulated cylinder, and the lamina can be accessed using at least one surgical tool to place a device, drug, or other therapeutic agent, the lamina lower and upper A device characterized in that the length of the wall changes to prevent the tip of the device from going into the central spinal canal. A surgically implantable device for placement on any divided edge of a patient's lamina that is divided on one or both sides using the device according to any one of claims 1-4. Surgically implantable device for preventing split posterior spinal elements from moving or rotating forward after laminectomy   6. The surgically implantable device of claim 5, wherein the device increases the length of the cut edge of the lamellar bone to prevent the divided edge from returning to its original position. A surgically implantable device characterized by:   6. The surgically implantable device of claim 5, wherein the device is secured to the segmented bone edge by at least one of clipping, compression, sliding, or friction. A surgically implantable device.   The surgically implantable device of claim 5, wherein the device is made of at least one of a metal, a ceramic, a polymer, and a bioabsorbable composite. Possible devices.   6. The surgically implantable device of claim 5, wherein the device is applicable based on direct visualization, magnification, fluoroscopy, CT, ultrasound, or MRI guidance. Surgically implantable device.

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